Because most viruses are extremely well adapted to their host organism, virus structure varies greatly. However, there are some general structural characteristics that all viruses share. All viruses have a capsid or head region that contains its genetic material. The capsid is made of proteins and glycoproteins.
The characteristics of viruses are as follows
1)They are enclosed in
a protective envelope
2)They are non cellular
3)They have a nucleic acid core containing DNA or RNA
4)They contain a protien coat called the caspid
5)They do not respire, they also donot metabolise and do not grow but they do reproduce
6)They have spikes which help them to attach to the host cell
7)Ribosomes and enzymes are absent which are needed for metabolism.
And all these are the characteristics of viruses. Hope this will help you